Moderate Sedation/
Analgesia (Conscious
Sedation)
Anuradha Patel
M.B.B.S., M.D., D.A., F.R.C.A. ( I ), D.A.B.A.
Assistant Professor,
Department of Anesthesiology and
Perioperative Medicine
UMDNJ, Newark
Introduction
These guidelines are designed to be applicable to
procedures performed in a variety of settings by
practitioners who are not specialists in
anesthesiology.The purpose of these is to allow
clinicians to provide their patients with the benefits
of sedation /analgesia, while minimizing associated
risks.These guidelines are intended to be general in
their application and broad in scope.
Depth of Sedation
Minimal Sedation (Anxiolysis)
- is a drug induced state during which patients
respond normally to verbal commands. Although
cognitive function and coordination may be
impaired, ventilatory and cardiovascular
functions are unaffected.
Depth of Sedation
Moderate Sedation/Analgesia (Conscious
Sedation)
- is a drug induced depression of consciousness during
which patients respond purposefully* to verbal
commands either alone or accompanied by light
tactile stimulation. No interventions are required to
maintain a patent airway, and spontaneous
ventilation is adequate. Cardiovascular function is
usually maintained.
Depth of Sedation
Deep Sedation/Analgesia
- is drug induced loss of consciousness during which
patients cannot be easily aroused but respond
purposefully* following repeated stimulation. The
ability to independently maintain ventilatory
function is often impaired.Patients may require
assistance in maintaining a patent airway and
positive pressure ventilation may be required.
Cardiovascular function may be impaired.
Depth of Sedation
General Anesthesia
- is a drug induced loss of consciousness during which
patients are not arousable, even by painful
stimulation. The ability to independently maintain
ventilatory is often impaired. Patients often require
assistance in maintaining a patent airway, and
positive pressure ventilation may be required.
Cardiovascular function may be impaired.
Depth of Sedation
• Protective airway reflexes-includes the ability of an
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individual to counteract noxious events, especially to defend
breathing passages against foreign material.
Reflex withdrawal from a painful stimulus is NOT considered
a purposeful response
Sedation is a continuum, it is not always possible to predict
how an individual will respond.
Practitioners intending to produce a given level of sedation
should be able to rescue patients whose level of sedation
becomes deeper than initially intended.
Locations of M.S./Analgesia
• Radiology Department
• Medical Special
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Procedures
Dental Clinic
Emergency Department
Progressive Care Units
Procedure Unit EYellow
• Critical Care Units
• Echocardiology Lab
• Cardiac
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Catheterization Lab
Clinics (Audiology,
Neurology)
Pre-operative holding
area
Patient Evaluation
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History/ Physical exam
Airway evaluation
Abnormalities of the major organ systems
Previous adverse experience with sedation
Drug allergies, current meds.,potential
interaction
Focused physical exam- vital signs, auscultation
of heart and lungs, evaluation of the airway
NPO status
Lab data
Patient Evaluation
Airway Evaluation
Mallampati Classification
• Relates tongue size to pharyngeal size
• Performed with the patient in the sitting position, the head
held in a neutral position, the mouth wide open, and the
tongue protruding to the maximum
• May vary if the patient is in the supine position (instead of
sitting)
• If the patients phonates, this falsely improves the view.
•If the patient arches his or her tongue, the uvula is falsely
obscured.
Patient Evaluation
Airway Evaluation
Mallampati Classification
Class I = visualization of the
soft palate, fauces, uvula,
anterior and posterior pillars.
Class II = visualization of the
soft palate, fauces and uvula.
Class III = visualization of the
soft palate and the base of the
uvula.
Class IV = soft palate is not
visible at all.
ASA Physical Status
• Class I- normal, healthy
• Class II- mild systemic disease
• Class III- severe systemic disease, e.g. HTN
COPD,
• Class IV-severe systemic disease that is a
constant threat to life, e.g. unstable angina
• Class V- moribund patient not expected to
live with or without the procedure
Patient Evaluation
When an anesthesiologist or other specialist may
be needed.
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ASA class III or higher
Airway abnormalities
Morbid obesity
Sleep apnea
Previously failed
sedation
Major allergy or
anaphylactic reaction
• Complex procedure
• Prolonged sedation
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needed
New procedure
Unusual position
Unusual location
Pre procedure preparation
• Informed consent
• Pre op fasting
– Clear liquids
– Breast milk
– Infant formula
– Milk
– Light meal
2h
4h
6h
6h
6h
Equipment
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Self inflating bag and mask
Oxygen – 2 outlets
Suction ( working )
Pulse oximeter, ECG monitor, BP. Monitor
? Capnometer
Pharmacologic antagonists
Emergency equipment – airway kit (age appropriate)
crash cart, defibrillator
Monitoring and Documentation
• Pre-procedure
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-V.S., SpO2
Procedure
-Continuous SpO2, E.C.G.
-V.S. q 5 min.
-L.O.C. q 5 min.(level of consciousness)
Post Procedure
-Continuous SpO2, V.S. q 5 min. for 15 min., then
q 15 min. until discharge criteria met
Personnel
1. The minimal number of available personnel should
be two:
The operator (performs procedure)
The monitor (administers drugs,
monitors airway and vital signs.
The second individual may assist with minor
interruptible tasks.
Both personnel must be credentialed in Moderate
Sedation/ Analgesia
Personnel
Personnel who can administer Moderate Sedation/
Analgesia or monitor a patient, include:
- A physician, or dentist who has been credentialed
Under the supervision of the above, the following
persons may administer M.S.
- CRNA, or a student CRNA,
- resident physician or resident dentist
-registered nurse, under special situations.
Training of Personnel
• Individuals responsible for patients should
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understand the pharmacology of agents used for
sedation and antagonists for opiates and
benzodiazepines.
Individuals monitoring patients should be able to
recognize associated complications.
One individual capable of estabilishing a patent
airway and positive pressure ventilation should
be present.
All personnel must be ACLS certified.
Discharge Criteria
Patients will be discharged according to the
Aldrete score. The patients must have a
score of ten.
Aldrete score is printed at the end of the Moderate
sedation/Analgesia record
Patients who receive reversal agents need to
remain in the procedure area for at least one
hour after the last dose.
Drugs
Drugs commonly used for M.S.
Meperidine (Demerol)
Morphine
Fentanyl (Sublimaze)
Ketamine
Diazepam (Valium)
Midazolam (Versed)
Droperidol (Inapsine)
Phenobarbital
Naloxone (Narcan)
Flumazenil (Romazicon)
Drugs
Drugs EXCLUDED for M.S./ Analgesia by
non-anesthesia staff are:
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Sodium Thiopental
Propofol
Brevital (metho hexital)
Etomidate
Sufentanil
Remifentanil
Combinations of Drugs
• IV.drugs should be given in small, incremental
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doses, titrated to end points of
analgesia/sedation.
Allow time for onset before repeating
Benzo. and opiates have synergistic effects
Non IV routes, eg. Oral,rectal,im.,tm.-allow
adequate time for absorption. Repeat doses not
recommended(unpredictable absorption)
Synergy
• Effects of Benzodiazepine and Opiate are
additive (synergistic)
• For example, 2 mg. Midazolam or 10 mg.
Morphine equals no apnea
• 1 mg Midazolam plus 5 mg morphine equals
apnea
Basic Considerations
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Low cardiac output equals slow onset
Consider the age of the brain
Consider the physical condition of the patient
What effect is desired?
Is post-procedure pain control needed?
When in trouble, back out
Titrate drugs to effect, wait for onset.
Reversal agents
• Specific antagonists, naloxone/flumazenil should
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be available
May be administered if apnea or hypoxemia
develops, but routine use is strongly discouraged.
Patients need to be observed longer in recovery
(at least 2 hrs.) if reversal agents are used.
Opiates
• Dose-dependent binding to opioid receptors
(especially mu) leads to:
– Analgesia
– Sedation
– Respiratory Depression
• Side effects:
– Nausea/vomiting
– Miosis
– Decreased Peristalsis
Morphine
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Average Dose:
Incremental Dose:
Time Between Doses:
Onset Time:
Duration of Effect:
Paradoxical Reaction
Pruritis
Anaphylactoid Reaction
Active Metabolites
5-15 mg
2.5 mg
5-10 min
5-10 min
3-4 hrs
Meperidine (Demerol)
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Average Dose:
50-150 mg
Incremental Dose:
25 mg
Time Between Doses:
5 min
Onset Time:
3-5 min
Duration of Effect:
2-3 hrs
Caution: Not used with MAO Inhibitors,
Antidepressants, Antiparkinsonian drugs
Remember “Libby Zion”
Active Metabolite can accumulate with renal
dysfunction
Benzodiazepines
• Enhance GABA transmission in CNS
• Most are lipid soluble only (except midazolam)
• Effects:
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Amnesia
Anticonvulsant
Anxiolytic
Behavioral disinhibition
Muscle relaxant
Diazepam
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Average Dose:
5-20 mg
Incremental Dose:
2.5 mg
Time Between Doses:
2-3 min
Onset Time:
1-2 min
Duration of Effect:
0.5-2 hrs
Several active metabolites prolong effects
Elimination t1/2
15-21 hrs
Midazolam (Versed)
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Average Dose:
1-5 mg
Incremental Dose:
0.5-1 mg
Time Between Doses:
3-5 min
Onset Time:
3-5 min
Duration of Effect:
0.5-2 hrs
Water and lipid soluble
Active metabolites, which are less potent
Elimination t½; 2-4 hrs
Diphenydramine
• Sedating antihistamine with anticholinergic
properties
• PO/IV/IM
• Maximum sedative effect 1-3 hrs, duration; 47 hrs
• Elimination t1/2: 2-8 hrs
Fentanyl (Sublimaze)
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Average Dose:
0.025-0.15 mg
Incremental Dose:
0.025 mg
Time Between Doses:
2-3 min
Onset Time:
1-2 min
Duration of Effect:
0.5- 1 hrs
Elimination t1/2:
3.1-6.6 hrs
May cause muscle rigidity
Naloxone (Narcan)
• Reversal of opiates
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Pain
Hypertension
Tachycardia
Ventricular dsyrhythmias
Pulmonary Edema
– Re-narcotization –Delayed respiratory depression
Naloxone (Narcan)
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Average Dose:
Incremental Dose:
Time Between Doses:
Onset Time:
Duration of Effect:
0.4 mg
0.04 mg
2-3 min
1-2 min
0.5-1 hrs
Flumazenil (Romazicon)
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Average Dose:
Incremental Dose:
Time Between Doses:
Onset Time:
Duration of Effect:
Resedation
Seizures
1 mg
0.2 mg
1 min
1-2 min
0.5-1.5 hrs
Performance Improvement
• All departments are responsible for PI activities
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related to moderate sedation
Data collection monthly, quarterly reporting of
complications on 6 PI indicators
All complications must be reported to Department of
Anesthesiology PI representative A copy of the
record needs to be sent to Dr. A Patel
Moderate sedation data is presented at the Invasive
Procedure Committee and Hospital PI committee
P.I. Indicators
• Respiratory complications- need for oral airway, bag
mask ventilation, intubation etc.
• Cardiovascular complications- hypotension, arrythmias,
etc.
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Use of reversal drugs
Admission to hospital,if outpatient
Pre sedation evaluation done
Discharge criteria documented